A SitABCD homologue from an avian pathogenic Escherichia coli strain mediates transport of iron and manganese and resistance to hydrogen peroxide

Microbiology ◽  
2006 ◽  
Vol 152 (3) ◽  
pp. 745-758 ◽  
Author(s):  
Mourad Sabri ◽  
Simon Léveillé ◽  
Charles M. Dozois
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Metal Ion ◽  
Growth Promotion ◽  
Coli Strain ◽  
Transport Systems ◽  
Virulence Plasmid ◽  
E Coli ◽  
K 12 ◽  
Iron And Manganese

An operon encoding a member of the family of ATP-binding cassette (ABC) divalent metal ion transporters, homologous to Salmonella enterica SitABCD, has been identified in the avian pathogenic Escherichia coli (APEC) strain χ7122. The sitABCD genes were located on the virulence plasmid pAPEC-1, and were highly similar at the nucleotide level to the chromosomally encoded sitABCD genes present in Shigella spp. A cloned copy of sitABCD conferred increased growth upon a siderophore-deficient E. coli strain grown in nutrient broth supplemented with the chelator 2,2′-dipyridyl. Ion rescue demonstrated that Sit-mediated growth promotion of this strain was due to the transport of iron. SitABCD mediated increased transport of both iron and manganese as demonstrated by uptake of 55Fe, 59Fe or 54Mn in E. coli K-12 strains deficient for the transport of iron (aroB feoB) and manganese (mntH) respectively. Isotope uptake and transport inhibition studies showed that in the iron transport deficient strain, SitABCD demonstrated a greater affinity for iron than for manganese, and SitABCD-mediated transport was higher for ferrous iron, whereas in the manganese transport deficient strain, SitABCD demonstrated greater affinity for manganese than for iron. Introduction of the APEC sitABCD genes into an E. coli K-12 mntH mutant also conferred increased resistance to the bactericidal effects of hydrogen peroxide. APEC strain χ7122 derivatives lacking either a functional SitABCD or a functional MntH transport system were as resistant to hydrogen peroxide as the wild-type strain, whereas a Δsit ΔmntH double mutant was more sensitive to hydrogen peroxide. Overall, the results demonstrate that in E. coli SitABCD represents a manganese and iron transporter that, in combination with other ion transport systems, may contribute to acquisition of iron and manganese, and resistance to oxidative stress.

Potentiation by L-cysteine of the bactericidal effect of hydrogen peroxide in Escherichia coli

1982 ◽  
Vol 152 (1) ◽  
pp. 81-88
Author(s):  
E H Berglin ◽  
M B Edlund ◽  
G K Nyberg ◽  
J Carlsson
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Metal Ion ◽  
Chelating Agent ◽  
Fold Increase ◽  
Bactericidal Effect ◽  
Anaerobic Conditions ◽  
Dna Breakage ◽  
E Coli ◽  
K 12

Under anaerobic conditions an exponentially growing culture of Escherichia coli K-12 was exposed to hydrogen peroxide in the presence of various compounds. Hydrogen peroxide (0.1 mM) together with 0.1 mM L-cysteine or L-cystine killed the organisms more rapidly than 10 mM hydrogen peroxide alone. The exposure of E. coli to hydrogen peroxide in the presence of L-cysteine inhibited some of the catalase. This inhibition, however, could not fully explain the 100-fold increase in hydrogen peroxide sensitivity of the organism in the presence of L-cysteine. Of other compounds tested only some thiols potentiated the bactericidal effect of hydrogen peroxide. These thiols were effective, however, only at concentrations significantly higher than 0.1 mM. The effect of L-cysteine and L-cystine could be annihilated by the metal ion chelating agent 2,2'-bipyridyl. DNA breakage in E. coli K-12 was demonstrated under conditions where the organisms were killed by hydrogen peroxide.

scholarly journals Representational Difference Analysis between Afa/Dr Diffusely Adhering Escherichia coli and Nonpathogenic E. coli K-12

2002 ◽  
Vol 70 (10) ◽  
pp. 5503-5511 ◽  
Author(s):  
Anne-Beatrice Blanc-Potard ◽  
Colin Tinsley ◽  
Isabel Scaletsky ◽  
Chantal Le Bouguenec ◽  
Julie Guignot ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Sequences ◽  
Effector Proteins ◽  
Representational Difference Analysis ◽  
Transport Systems ◽  
Difference Analysis ◽  
E Coli ◽  
Tract Infections ◽  
K 12 ◽  
Specific Sequences

ABSTRACT Diffusely adhering Escherichia coli strains harboring Afa/Dr adhesins (Afa/Dr DAEC) have been associated with diarrhea and urinary tract infections (UTIs). The present work is the first extensive molecular study of a Afa/Dr DAEC strain using the representational difference analysis technique. We have searched for DNA sequences present in strain C1845, recovered from a diarrheagenic child, but absent from a nonpathogenic K-12 strain. Strain C1845 harbors part of a pathogenicity island (PAICFT073) and several iron transport systems found in other E. coli pathovars. We did not find genes encoding factors known to subvert host cell proteins, such as type III secretion system or effector proteins. Several C1845-specific sequences are homologous to putative virulence genes or show no homology with known sequences, and we have analyzed their distribution among Afa/Dr and non-Afa/Dr clinical isolates and among strains from the E. coli Reference Collection. Three C1845-specific sequences (MO30, S109, and S111) have a high prevalence (77 to 80%) among Afa/Dr strains and a low prevalence (12 to 23%) among non-Afa/Dr strains. In addition, our results indicate that strain IH11128, an Afa/Dr DAEC strain recovered from a patient with a UTI, is genetically closely related to strain C1845.

scholarly journals The lipopolysaccharide of the mastitis isolate Escherichia coli strain 1303 comprises a novel O-antigen and the rare K-12 core type

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1750-1760 ◽  
Author(s):  
Katarzyna A. Duda ◽  
Buko Lindner ◽  
Helmut Brade ◽  
Andreas Leimbach ◽  
Elżbieta Brzuszkiewicz ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Inner Core ◽  
Bovine Mastitis ◽  
Outer Core ◽  
Coli Strain ◽  
Core Oligosaccharide ◽  
2D Nmr Spectroscopy ◽  
E Coli ◽  
O Antigen ◽  
K 12

Mastitis represents one of the most significant health problems of dairy herds. The two major causative agents of this disease are Escherichia coli and Staphylococcus aureus. Of the first, its lipopolysaccharide (LPS) is thought to play a prominent role during infection. Here, we report the O-antigen (OPS, O-specific polysaccharide) structure of the LPS from bovine mastitis isolate E. coli 1303. The structure was determined utilizing chemical analyses, mass spectrometry, and 1D and 2D NMR spectroscopy methods. The O-repeating unit was characterized as -[→4)-β-d-Quip3NAc-(1→3)-α-l-Fucp2OAc-(1→4)-β-d-Galp-(1→3)-α-d-GalpNAc-(1→]- in which the O-acetyl substitution was non-stoichiometric. The nucleotide sequence of the O-antigen gene cluster of E. coli 1303 was also determined. This cluster, located between the gnd and galF genes, contains 13 putative open reading frames, most of which represent unknown nucleotide sequences that have not been described before. The O-antigen of E. coli 1303 was shown to substitute O-7 of the terminal ld-heptose of the K-12 core oligosaccharide. Interestingly, the non-OPS-substituted core oligosaccharide represented a truncated version of the K-12 outer core – namely terminal ld-heptose and glucose were missing; however, it possessed a third Kdo residue in the inner core. On the basis of structural and genetic data we show that the mastitis isolate E. coli 1303 represents a new serotype and possesses the K-12 core type, which is rather uncommon among human and bovine isolates.

scholarly journals Iha from an Escherichia coli Urinary Tract Infection Outbreak Clonal Group A Strain Is Expressed In Vivo in the Mouse Urinary Tract and Functions as a Catecholate Siderophore Receptor

2006 ◽  
Vol 74 (6) ◽  
pp. 3427-3436 ◽  
Author(s):  
Simon Léveillé ◽  
Mélissa Caza ◽  
James R. Johnson ◽  
Connie Clabots ◽  
Mourad Sabri ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Growth Promotion ◽  
Clonal Group ◽  
E Coli ◽  
Group A ◽  
K 12

ABSTRACT Virulence factors of pathogenic Escherichia coli belonging to a recently emerged and disseminated clonal group associated with urinary tract infection (UTI), provisionally designated clonal group A (CGA), have not been experimentally investigated. We used a mouse model of ascending UTI with CGA member strain UCB34 in order to identify genes of CGA that contribute to UTI. iha was identified to be expressed by strain UCB34 in the mouse kidney using selective capture of transcribed sequences. iha from strain UCB34 demonstrated a siderophore receptor phenotype when cloned in a catecholate siderophore receptor-negative E. coli K-12 strain, as shown by growth promotion experiments and uptake of 55Fe complexed to enterobactin or its linear 2, 3-dihydroxybenzoylserine (DHBS) siderophore derivatives. Siderophore-mediated growth promotion by Iha was TonB dependent. Growth and iron uptake were more marked with linear DHBS derivatives than with purified enterobactin. The reported phenotype of adherence to epithelial cells conferred by expressing iha from a multicopy cloning vector in a poorly adherent E. coli K-12 host strain was confirmed to be specific to iha, in comparison with other siderophore receptor genes. iha expression was regulated by the ferric uptake regulator Fur and by iron availability, as shown by real-time reverse transcriptase PCR. In a competitive infection experiment using the mouse UTI model, wild-type strain UCB34 significantly outcompeted an isogenic iha null mutant. Iha thus represents a Fur-regulated catecholate siderophore receptor that, uniquely, exhibits an adherence-enhancing phenotype and is the first described urovirulence factor identified in a CGA strain.

Characterization of the flexible genome complement of the commensal Escherichia coli strain A0 34/86 (O83 : K24 : H31)

Microbiology ◽  
2005 ◽  
Vol 151 (2) ◽  
pp. 385-398 ◽  
Author(s):  
Jana Hejnova ◽  
Ulrich Dobrindt ◽  
Radka Nemcova ◽  
Christophe Rusniok ◽  
Alojz Bomba ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Gene Clusters ◽  
Coli Strain ◽  
Bac Clone ◽  
Sequence Comparisons ◽  
Multiple Sequence ◽  
E Coli ◽  
Gut Colonization ◽  
K 12

Colonization by the commensal Escherichia coli strain A0 34/86 (O83 : K24 : H31) has proved to be safe and efficient in the prophylaxis and treatment of nosocomial infections and diarrhoea of preterm and newborn infants in Czech paediatric clinics over the past three decades. In searching for traits contributing to this beneficial effect related to the gut colonization capacity of the strain, the authors have analysed its genome by DNA–DNA hybridization to E. coli K-12 (MG1655) genomic DNA arrays and to ‘Pathoarrays’, as well as by multiplex PCR, bacterial artificial chromosome (BAC) library cloning and shotgun sequencing. Four hundred and ten E. coli K-12 ORFs were absent from A0 34/86, while 72 out of 456 genes associated with pathogenicity islands of E. coli and Shigella were also detected in E. coli A0 34/86. Furthermore, extraintestinal pathogenic E. coli-related genes involved in iron uptake and adhesion were detected by multiplex PCR, and genes encoding the HlyA and cytotoxic necrotizing factor toxins, together with 21 genes of the uropathogenic E. coli 536 pathogenicity island II, were identified by analysis of 2304 shotgun and 1344 BAC clone sequences of A0 34/86 DNA. Multiple sequence comparisons identified 31 kb of DNA specific for E. coli A0 34/86; some of the genes carried by this DNA may prove to be implicated in the colonization capacity of the strain, enabling it to outcompete pathogens. Among 100 examined BAC clones roughly covering the A0 34/86 genome, one reproducibly conferred on the laboratory strain DH10B an enhanced capacity to persist in the intestine of newborn piglets. Sequencing revealed that this BAC clone carried gene clusters encoding gluconate and mannonate metabolism, adhesion (fim), invasion (ibe) and restriction/modification functions. Hence, the genome of this clinically safe and highly efficient colonizer strain appears to harbour many ‘virulence-associated’ genes. These results highlight the thin line between bacterial ‘virulence’ and ‘fitness' or ‘colonization’ factors, and question the definition of enterobacterial virulence factors.

Cloning and expression of the beta-D-phosphogalactoside galactohydrolase gene of Lactobacillus casei in Escherichia coli K-12

1982 ◽  
Vol 152 (3) ◽  
pp. 1138-1146
Author(s):  
L J Lee ◽  
J B Hansen ◽  
E K Jagusztyn-Krynicka ◽  
B M Chassy
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Casei ◽  
Specific Activity ◽  
Protein Product ◽  
Coli Strain ◽  
Cloning And Expression ◽  
E Coli ◽  
Lactose Metabolism ◽  
Gene Coding ◽  
K 12

Lactose metabolism in Lactobacillus casei 64H is associated with the presence of plasmid pLZ64. This plasmid determines both phosphoenolpyruvate-dependent phosphotransferase uptake of lactose and beta-D-phosphogalactoside galactohydrolase. A shotgun clone bank of chimeric plasmids containing restriction enzyme digest fragments of pLZ64 DNA was constructed in Escherichia coli K-12. One clone contained the gene coding for beta-D-phosphogalactoside galactohydrolase on a 7.9-kilobase PstI fragment cloned into the vector pBR322 in E. coli strain chi 1849. The beta-D-phosphogalactoside galactohydrolase enzyme isolated from E. coli showed no difference from that isolated from L. casei, and specific activity of beta-D-phosphogalactoside galactohydrolase was stimulated 1.8-fold in E. coli by growth in media containing beta-galactosides. A restriction map of the recombinant plasmid was compiled, and with that information, a series of subclones was constructed. From an analysis of the proteins produced by minicells prepared from transformant E. coli cells containing each of the recombinant subclone plasmids, it was found that the gene for the 56-kilodalton beta-D-phosphogalactoside galactohydrolase was transcribed from an L. casei-derived promoter. The gene for a second protein product (43 kilodaltons) was transcribed in the opposite direction, presumably under the control of a promoter in pBR322. The relationship of this second product to the lactose metabolism genes of L. casei is at present unknown.

scholarly journals A Commensal Gone Bad: Complete Genome Sequence of the Prototypical Enterotoxigenic Escherichia coli Strain H10407

2010 ◽  
Vol 192 (21) ◽  
pp. 5822-5831 ◽  
Author(s):  
Lisa C. Crossman ◽  
Roy R. Chaudhuri ◽  
Scott A. Beatson ◽  
Timothy J. Wells ◽  
Mickael Desvaux ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Sequence ◽  
Epidemiological Data ◽  
Coli Strain ◽  
Enterotoxigenic Escherichia Coli ◽  
E Coli ◽  
Extraintestinal Disease ◽  
K 12 ◽  
Genetic Context ◽  
Complete Genomic

ABSTRACT In most cases, Escherichia coli exists as a harmless commensal organism, but it may on occasion cause intestinal and/or extraintestinal disease. Enterotoxigenic E. coli (ETEC) is the predominant cause of E. coli-mediated diarrhea in the developing world and is responsible for a significant portion of pediatric deaths. In this study, we determined the complete genomic sequence of E. coli H10407, a prototypical strain of enterotoxigenic E. coli, which reproducibly elicits diarrhea in human volunteer studies. We performed genomic and phylogenetic comparisons with other E. coli strains, revealing that the chromosome is closely related to that of the nonpathogenic commensal strain E. coli HS and to those of the laboratory strains E. coli K-12 and C. Furthermore, these analyses demonstrated that there were no chromosomally encoded factors unique to any sequenced ETEC strains. Comparison of the E. coli H10407 plasmids with those from several ETEC strains revealed that the plasmids had a mosaic structure but that several loci were conserved among ETEC strains. This study provides a genetic context for the vast amount of experimental and epidemiological data that have been published.

scholarly journals Manganese Is Required for the Rapid Recovery of DNA Synthesis following Oxidative Challenge in Escherichia coli

2019 ◽  
Vol 201 (24) ◽  
Author(s):  
Corinne R. Hutfilz ◽  
Natalie E. Wang ◽  
Chettar A. Hoff ◽  
Jessica A. Lee ◽  
Brandy J. Hackert ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Dna Synthesis ◽  
Genomic Dna ◽  
Rapid Recovery ◽  
Content Type ◽  
E Coli ◽  
Oxidative Challenge ◽  
Alternative Enzymes ◽  
Iron And Manganese

ABSTRACT Divalent metals such as iron and manganese play an important role in the cellular response to oxidative challenges and are required as cofactors by many enzymes. However, how these metals affect replication after oxidative challenge is not known. Here, we show that replication in Escherichia coli is inhibited following a challenge with hydrogen peroxide and requires manganese for the rapid recovery of DNA synthesis. We show that the manganese-dependent recovery of DNA synthesis occurs independent of lesion repair, modestly improves cell survival, and is associated with elevated rates of mutagenesis. The Mn-dependent mutagenesis involves both replicative and translesion polymerases and requires prior disruption by H2O2 to occur. Taking these findings together, we propose that replication in E. coli is likely to utilize an iron-dependent enzyme(s) that becomes oxidized and inactivated during oxidative challenges. The data suggest that manganese remetallates these or alternative enzymes to allow genomic DNA replication to resume, although with reduced fidelity. IMPORTANCE Iron and manganese play important roles in how cell’s cope with oxygen stress. However, how these metals affect the ability of cells to replicate after oxidative challenges is not known. Here, we show that replication in Escherichia coli is inhibited following a challenge with hydrogen peroxide and requires manganese for the rapid recovery of DNA synthesis. The manganese-dependent recovery of DNA synthesis occurs independently of lesion repair and modestly improves survival, but it also increases the mutation rate in cells. The results imply that replication in E. coli is likely to utilize an iron-dependent enzyme(s) that becomes oxidized and inactivated during oxidative challenges. We propose that manganese remetallates these or alternative enzymes to allow genomic DNA replication to resume, although with reduced fidelity.

scholarly journals Identification of a Copper-Responsive Two-Component System on the Chromosome of Escherichia coli K-12

2000 ◽  
Vol 182 (20) ◽  
pp. 5864-5871 ◽  
Author(s):  
George P. Munson ◽  
Deborah L. Lam ◽  
F. Wayne Outten ◽  
Thomas V. O'Halloran
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Syringae ◽  
Metal Ion ◽  
Copper Ions ◽  
Copper Ion ◽  
Regulatory System ◽  
Copper Resistance ◽  
E Coli ◽  
Two Component ◽  
K 12

ABSTRACT Using a genetic screen we have identified two chromosomal genes,cusRS (ylcA ybcZ), from Escherichia coli K-12 that encode a two-component, signal transduction system that is responsive to copper ions. This regulatory system is required for copper-induced expression of pcoE, a plasmid-borne gene from the E. coli copper resistance operon pco. The closest homologs of CusR and CusS are plasmid-borne two-component systems that are also involved in metal responsive gene regulation: PcoR and PcoS from the pcooperon of E. coli; CopR and CopS from thecop operon, which provides copper resistance toPseudomonas syringae; and SilR and SilS from thesil locus, which provides silver ion resistance toSalmonella enterica serovar Typhimurium. The genescusRS are also required for the copper-dependent expression of at least one chromosomal gene, designated cusC(ylcB), which is allelic to the recently identified virulence gene ibeB in E. coli K1. Thecus locus may comprise a copper ion efflux system, because the expression of cusC is induced by high concentrations of copper ions. Furthermore, the translation products of cusCand additional downstream genes are homologous to known metal ion antiporters.

scholarly journals Identification and Characterization of a Novel ABC Iron Transport System, fit, in Escherichia coli

2006 ◽  
Vol 74 (12) ◽  
pp. 6949-6956 ◽  
Author(s):  
Zhiming Ouyang ◽  
Richard Isaacson
Keyword(s):  
Escherichia Coli ◽  
Growth Promotion ◽  
Hypothetical Protein ◽  
Bidirectional Promoter ◽  
Intracellular Iron ◽  
E Coli ◽  
K 12 ◽  
Identification And Characterization

ABSTRACT A putative ABC transporter, fit, with significant homology to several bacterial iron transporters was identified in Escherichia coli. The E. coli fit system consists of six genes designated fitA, -B, -C, -D, -E, and -R. Based on DNA sequence analysis, fit encodes an outer membrane protein (FitA), a periplasmic binding protein (FitE), two permease proteins (FitC and -D), an ATPase (FitB), and a hypothetical protein (FitR). Introduction of the E. coli fit system into E. coli strain K-12 increased intracellular iron content and transformed bacteria were more sensitive to streptonigrin, which suggested that fit transports iron in E. coli. Expression of fit was studied using a lacZ reporter assay. A functional, bidirectional promoter was identified in the intergenic region between genes fitA and fitB. The expression of the E. coli fit system was found to be induced by iron limitation and repressed when Fe2+ was added to minimal medium. Several fit mutants were created in E. coli using an in vitro transposon mutagenesis strategy. Mutations in fit did not affect bacterial growth in iron-restricted media. Using a growth promotion test, it was found that fit was not able to transport enterobactin, ferrichrome, transferrin, and lactoferrin in E. coli.

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